ON PERIODICAL OPHTHALMIA. 
383 
1830, was castrated by an itinerant gelder, without any prepara¬ 
tion of the horse for such an operation ; and after a good deal of 
frizzling with the iron, and scalding from ointment melted inside 
the scrotum with the same instrument, he was in a fair way to 
finish his last race; but he recovered, and ophthalmia appeared in 
his eyes,—acute inflammation attacking first one organ and then 
the other, and which ultimately destroyed them. 
I have frequently witnessed ophthalmia supervene upon phleg¬ 
monous inflammation of the hind extremities, and upon grease. 
I believe metastasis of inflammation to be a more frequent 
source of ophthalmia in the horse than has been generally consi¬ 
dered. 
Mr. J. Castley, veterinary surgeon, 12th Royal Lancers, informs 
us, that he has frequently observed ophthalmia occur after long- 
continued attacks of diabetes; and he relates one particular case 
in which inflammation alternately occurred in the eyes and the 
hind leg. As it appeared in the one, it disappeared in the other : 
and, as Mr. Castley observes, it is probable any great constitu¬ 
tional disturbance may give rise to ophthalmia. When the system 
has acquired an inflammatory diathesis, the various exciting 
causes of disease are in full power; and we are not yet sufficiently 
intelligent to exemplify the principle by which the eye in this 
instance, the brain in the next, or the lungs or the bowels in 
others, become the seat of acute inflammation. 
The horse is more subject to ophthalmia, and all inflammatory 
diseases, from five to six years old than any other period ; un¬ 
doubtedly from the fulness of habit or plethoric state of the 
system to which the animal's arrival at maturity subjects him. 
Four-year-olds are very common subjects of internal ophthalmia ; 
and it is not improbable that changing and cutting of the teeth, 
particularly when the horse is stabled and feeding on hard meat, 
may occasionally produce it. 
Professor Coleman lays much stress on a poisonous gas gene¬ 
rated in the stable by a combination of the exhalation from the 
dung, urine, &c., with the expired air and perspirable vapour of 
the horse, as producing ophthalmia, and, in fact, most other dis¬ 
eases : but much as I respect the talent and genius of the 
Professor, 1 must confess my disbelief in this malaria. There is 
but little necessity to commune with this mystical agency, to dis¬ 
cover sufficient exciting causes of disease in our domesticated 
horses, when we consider the change of temperature to which 
they are exposed, consequent on keeping our stables much above 
the temperature of the out-door atmosphere—the bad hay and 
corn, the irregular and improper feeding, the unequal exertion, 
and I may say ill-treatment they occasionally experience. 
